The performance of the power amplifier determines the detection capability of 77 GHz automotive radar, and the bias circuit is one of the most important parts of a silicon-germanium power amplifier. In this paper,we d...The performance of the power amplifier determines the detection capability of 77 GHz automotive radar, and the bias circuit is one of the most important parts of a silicon-germanium power amplifier. In this paper,we discussed and designed an on-chip bias circuit based on a silicon-germanium heterojunction bipolar transistor,which is used for the W-band silicon-germanium power amplifier. Considering the low breakdown voltage and the correlation between characteristic frequency and bias current density of the silicon-germanium heterojunction bipolar transistor, the bias circuit is designed to improve the breakdown voltage of the power amplifier and meet the W band characteristic frequency at the same time. The simulation results show that the designed bias circuit can make the amplifier operate normally from-40 to 125 ℃. In addition, the output power and smooth controllability of the power amplifier can be adjusted by controlling the bias circuit.展开更多
文摘The performance of the power amplifier determines the detection capability of 77 GHz automotive radar, and the bias circuit is one of the most important parts of a silicon-germanium power amplifier. In this paper,we discussed and designed an on-chip bias circuit based on a silicon-germanium heterojunction bipolar transistor,which is used for the W-band silicon-germanium power amplifier. Considering the low breakdown voltage and the correlation between characteristic frequency and bias current density of the silicon-germanium heterojunction bipolar transistor, the bias circuit is designed to improve the breakdown voltage of the power amplifier and meet the W band characteristic frequency at the same time. The simulation results show that the designed bias circuit can make the amplifier operate normally from-40 to 125 ℃. In addition, the output power and smooth controllability of the power amplifier can be adjusted by controlling the bias circuit.